A pump includes a rotor and a pump housing. The rotor is rotatable about a rotation axis and comprises a rotor hub and a rotor collar. The rotor collar extends from the rotor hub in the radial direction and encircles the rotor hub in an undulating manner. The pump housing comprises a first axial housing component, a central annular housing component, and a second axial housing component. A pump duct is formed (i) in the axial direction by the first and second housing components and (ii) in the radial direction by the central annular housing component and the rotor.

An electrically driven gerotor pump has a gerotor which comprises a stationary outer gerotor element with an inner toothing that is axially delimited by two chamber walls, wherein each chamber-forming foot section of the inner toothing is paired with a pressure valve which is connected to the outlet. The gerotor also comprises an inner gerotor element with an outer toothing which is guided in the outer gerotor element in a circumferential manner on an eccentric section of the shaft and is mounted in, a rotatable manner so as to mesh with the inner toothing.

It is assumed that a distance between a center portion of fixed scroll end plate and an outer peripheral portion at a distal end of fixed spiral wrap of fixed scroll is Ds, and that a distance between a center portion of orbiting scroll end plate and a portion included in a bottom face of an orbiting spiral wrap of orbiting scroll and facing the outer peripheral portion at the distal end of the fixed spiral wrap of the fixed scroll is Do. Further, assuming that an orbiting radius of orbiting scroll is ε, the orbiting radius being a distance between a center of eccentric shaft and a center of driving shaft, a relationship Ds+ε≤Do is satisfied.

A rotary piston engine comprises a housing (10), which forms an interior space (11), and at least two rotary pistons (20, 30), which are arranged in the interior space (11). Formed on the interior space (11) are an inlet opening (13) and an outlet opening (15) to guide a fluid through the interior space (11). The rotary pistons (20, 30) are thereby driven by fluid flowing through. Each rotary piston (20, 30) has on its outer circumference at least two sealing strips (21, 31). According to the invention each rotary piston (20, 30) comprises at least two cavities (27, 37), in each of which a tube (38B) or an elastic solid rod is arranged. The sealing strips (21, 31) project into the cavities and against the tube (38B) received therein or the elastic solid rod. Through the tube (38B) or the rod, the sealing strips (21, 31) are pushed radially outwards.

A scroll fluid machine that attenuates the bending stress applied to the base of a wall body having an inclined section. The scroll fluid machine is provided with a wall body inclined section in which the distance between the facing surfaces of an end plate of a fixed scroll and an end plate of a rotating scroll that face each other continuously decreases from the outer circumferential side toward the inner circumferential side. A mesh clearance that is a gap between wall bodies formed when the wall bodies mesh with each other is larger on the outer circumferential side of the inclined section than on the inner circumferential side of the inclined section. The mesh clearance is made larger by drawing the wall surface of a wall body further back toward the central side of the wall body in the thickness direction than the original wall surface profile thereof.

A screw compressor includes a casing, a motor provided in the casing, a screw rotor inserted into a cylinder in the casing, a bearing holder, a drive shaft, a first bearing, and a second bearing. The cylinder is formed on a lateral side of the motor. The bearing holder is disposed on an opposite side of the screw rotor from the motor and adjacent to the screw rotor. The drive shaft is connected to the motor and the screw rotor. The first bearing is disposed adjacent to the screw rotor. The second bearing is disposed adjacent to the motor in an axial direction of the drive shaft. At least a portion of the first bearing is disposed inside the screw rotor.

A scroll compressor includes a fixed scroll having a spiral-shaped fixed-side wrap, and a movable scroll having a spiral-shaped movable-side wrap. The fixed-side wrap and the movable-side wrap mesh with each other to form a compression chamber. The movable scroll is rotated eccentrically with respect to the fixed scroll to discharge a refrigerant compressed in the compression chamber from a single discharge port open at a starting end of turns of the fixed-side wrap. A first port expanding portion and a second port expanding portion communicating with the single discharge port to enlarge a passage area of the discharge port are arranged at an interval in a circumferential direction on a root side of the fixed-side wrap of the fixed scroll.

In a rotor in rotor configuration, a pump has inward projections on an outer rotor and outward projections on an inner rotor. The outer rotor is driven and the projections mesh to create variable volume chambers. The outer rotor may be driven in both directions. In each direction, the driving part (first inward projection) of the outer rotor contacts a sealing surface on one side of an outward projection of the inner rotor, while a gap is left between a sealing surface of the other side of the outward projection and a second inward projection. The gap may have uniform width along its length in the radial direction, while in a direction parallel to the rotor axis it may be discontinuous or have variable size to create flow paths for gases.

An internal combustion engine includes one or more pairs of non-meshing, externally timed rotors disposed within a housing in an expander module and a compressor module. Each rotor includes a cylindrical, center main body including a first end, a second end opposite the first end, an elongate portion extending between the ends and a first peripheral surface portion and a second peripheral surface portion and a bore extending through a center of the main body from the first end to the to second end. The rotors each have a groove extending along outer peripheral edge portions of the rotor. A pair of tip seals is disposed in the grooves. A pair of apex seals is disposed on the first peripheral surface portion and the second peripheral surface portion and an axially floating end plate is disposed at an end of the housing.

An eccentric screw pump has a stator, a rotor rotating in the stator, a drive, and a pump housing connected to the stator and having at least one inlet or outlet opening for a medium to be conveyed. A connecting shaft driven by the drive rotates concentrically with an axis, and a connecting housing connected between the pump housing and the drive at least partially surrounds the connecting shaft. A coupling-side shaft seal lies between the connecting shaft and the connecting housing, and a coupling rod in the pump housing is connected to the connecting shaft at a drive-side end and to the rotor at a rotor-side end thereof and generating eccentric movement of the rotor-side end on concentric rotation of the connecting shaft. A sensor is mounted in or on the connecting housing adjacent the connecting shaft for detecting or measuring deviation from axially concentric rotation thereof.